FATAL EPIDEMIC INTESTINAL DISEASE OF GOLDFISH. 
53 ' 
doubt led to the condition observed by my co-author, namely, falling to the 
bottom of the tank and inability to rise to the surface of the water. 
Histology of the Disease. 
This may best be described in stages illustrated by the figures (Plate II.). 
Intestine . — First stage : Acute inflammatory exudate in the villi and 
submucosa (Figure 2, left, and Figure 3). 
Second stage : Sloughing of the mucosa but epithelial cells staining well 
(Figure 4). 
Third stage : Sloughing with marked cellular degeneration of epithelium. 
General structure of the gut is fairly well maintained (Figure 5). 
Fourth stage : Necrosis amd sloughing of the whole villi, musculature 
still intact (Figure 6). 
Fifth stage : Complete necrosis of the whole intestinal wall. Amorphous 
sloughs in the lumen (Figure 7). 
Liver . — This organ showed complete necrosis, the nuclei of the cells having 
completely degenerated while their cytoplasm stained very feebly with cytoplasmic 
dyes. There was no evidence of primary fatty degeneration so I judge the 
intoxication to have been of an overwhelming kind, similar to acute necrosis 
in the human. The general texture of the viscus was unrecognisable. 
Etiology. 
The three fish that form the subject of the above comment were 
submitted to me in formalin. Successful cultures of the intestinal flora could 
not then be anticipated. Direct smears showed as the only significant feature 
the presence of a subterminal spored Clostridium. 
i had the opportunity of culturing the gut contents of another fish 
which had died of the same disease. Direct smears showed an unusual organism 
in my experience of intestinal flora, namely, a small non-motile Gram-negative 
diplobacillus in almost all cases encapsuled. Very rarely what appeared to be 
the same organism was single and not encapsuled. Variation in size was 
considerable, from 1*25 to 4 microns averaging about 2 microns in length by 
0-5 micron in width. An emulsion of gut content was plated out on McConkey’s 
medium. The organism evidently fermented lactose as no pale colonies showed 
up. Examination showed the diplobacillus still present, and to obtain a pure 
culture a subculture was made on a plain agar plate. No growth of the germ 
desired was obtained, or at least it was overgrown to such an extent that it 
could not be recovered. A similar fate befell those on the first plate, and the 
organism, evidently very delicate, was lost. I do not suggest this bacillus is 
the cause of the disease, but an organism of the kind noted seemed to me so 
unusual that I judged it wise to follow it up, and I mention it here for the- 
information of workers in this field. 
